Mining machine bit patterns



March 6, 1956 A. BARRETT MINING MACHINE BIT PATTERNS Filed April 29, 1950 2 Sheet$-$heet 1 FIG. I.

CHAINI CHAINZ CHA|N3 CHAIN4 I A 1/ A \l A \I A INVENTOR= ARTH L. BA ETT I BY 1F? ATTORNEY March 6, 1956 BARRETT 2,737,378

MINING MACHINE BIT PATTERNS Filed April 29, 1950 2 Sheets-Sheet 2 FIG. 3.

V CHAIN I CHAIN 2 CHAIN 3 CHAIN 4 INVENTOR= ARTHUR L. B RRETT ATTORNEY United States Patent MINING MACHINE BIT PATTERNS Arthur L. Barrett, Franklin, Pa., assignor to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application April 29, 1950, Serial No. 159,115 13 Claims. (Cl. 262-29) This invention relates to bit patterns for the disintegrating elements of a vein-attacking and disintegrating instrument of a continuous miner, particularly to bit patterns for continuous miners of the type disclosed in copending applications Ser. No. 11,688, filed February 27, 1948; Ser. No. 102,995, filed July 5, 1949; Ser. No. 102,996, filed July 5, 1949; Serial No. 442,518, filed July 12, 1954, and in my copending application Ser. No. 53,536, filed October 8, 1948, now abandoned, and assigned to the assignee of this invention.

In the operation of mining machines of the type referred to above, there has been some difficulty experienced in excessive vibration of the vein-attacking and disintegrating instrument. Such excessive vibration puts great strains on the machine and may result in failure of certain structural details. It has been found that much of the excessive vibration is caused by too great a disparity in the penetration factors of rows of bits as arranged in the vein-attacking and disintegrating instrument.

It is, accordingly, an object of this invention to provide improved bit patterns for the vein-attacking and disintegrating instrument of a continuous mining machine which will result in improved and smootheroperation of the machine. This and other objects are achieved in bit patterns in which the various rows of bits are arranged with penetration factor totals which do not differ so much as to shock the entire machine when one row of bits leaves contact with the mineral in the solid and another row to contact the mineral accomplishes such contact.

In the drawings:

Fig. 1 is a schematic diagram showing the location of bits in one embodiment of the invention.

Fig. 2 is a cross section through a vein-attacking and disintegrating instrument of the type shown in the aboveidentified patent applications, and

Fig. 3 is a view similar to Fig. 1, but showing another embodiment of the invention.

As will be understood by those skilled in the art after reference to the above-identified patent applications, a vein-attacking and disintegrating instrument such as is shown in section at 2 of Fig. 2 is provided with means to support a plurality of disintegrating elements or bits 4 for movement in substantially parallel orbital paths. It will of course be understood that the orbital paths may take any desired form or shape. In the embodiment shown, the orbital paths are provided by chains, some of the links of which are shown at 6; the chainscar-ry bit blocks such as are shown at 8.

As will be understood by reference to the aboveidentified patent applications, the vein-attacking and disintegrating instrument 2 is mounted for movement into a solid vein of mineral in a direction which is substantially perpendicular to the direction of rectilinear'travel or movement of the bits in their orbital paths. Thus, in the embodiment shown in Fig. 2, the bits move in orbital paths in a direction perpendicular to the plane of the paper, and the vein-attacking and disintegrating instrugent itself is moving in a vertical direction as seen in It will be understood that the bits 4 need not move in exactly those orbits which will result from the precise details of vein-attacking and disintegrating instrument shown in Fig. 2 and in the above-identified patent applications. In order to make for a clearer and more easily understood explanation of bit arrangements made according to this invention, it will be understood. by those skilled in the art that the patterns shown in Figs. 1 and 3 are shown in their developed condition. It is as though the chains were broken at one transverse plane and thereafter spread out on a flat surface. Such a developed bit pattern can be discussed independently of the precise type of orbit in which the bits move, whether that orbit be elliptical, circular or some other shape.

The bits in the outside chains, indicated as chains 1 and 4 in Figs. 1 and 3, carry eight bits. The substantially vertical bit indicated as 45 has its tip projecting farther from the block than the tips of all remaining bits. The next highest bits are those indicated as 44 and are on each side of bit 45 and approximately 13 from the vertical. Bits 4 are next adjacent to bits 44, about 24 from the vertical, and have their tips projecting upward less than bits 44. Bits 42 are next adjacent to bits 43, about 40 from the vertical, and their tips are below the tips of bits 43. Bits 41, present only in chains 1 and 4, are the lowest of the bits, and are arranged about 55 from the vertical.

It will be understood that the bits are mounted in bit blocks in a well known manner, and that the topmost surface of all the bit blocks. will be at approximately the same distance from a plate 10' which provides a sliding surface for the'chains carrying the bits.

The bits are preferably arranged in the blocks in' such a manner as to give a variation in distance of the tips from the blocks. which increases from bits 41 to bits 45. It will be understood that the distance of the tip of the bit will be measured, in the plane of the orbit of such tip, from the level of the highest bit block, where the height of the bit blocks varies substantially. The ratio of the distance of a bit tip from the highest block in the chain tothe distance of the tip of bit 41 from the top of the highest block will be taken as the penetration factor of a bit. Thus, according to this definition, bits 41 will have a penetration factor of unity. The values for the other bits may be as set forth. in the following table, although it will of course be understood that variations from the principle of the invention.

. Tio .Dis- Penetration Bit Position tame Factor It will be noted that the horizontal bit rows in Figs. 1 and 3 are numbered at intervals of 5 along the right sides of these figures. These rows are substantially perpendicular to the orbital paths and are also substantially parallel to each other.

The vertical rows shown in Figs. 1 and 3 are also numbered and the numbers indicate the positions of the bit tips. Thus, rows 1 indicate the positions of the tips of bits 41, rows 2 indicate the positions of the tips of bits 42, etc. The positions of the 45 bits are shown by white circles and the positions of all other bits are shown in solid circles.

The: arrangement: of the bits in chains provides a Patented Mar. 6,. 1956 plurality of groups (of bits) substantially parallel to the orbital paths. It will be understood by those skilled in the art that some advantages of the invention may be realized by similar groupings which are not dependent or based upon the chain arrangement. Accordingly, the bits could be similarly grouped even though moved orbitally by some other means; or the bits on four chains could be arranged in five groups, for example.

If we now take the bits one horizontal row at a time, and add up the peneration factors of the bits in a row, we have in row 1 three bits in position and one bit in position 1, and these four bits have a total penetration factor of 11.35, tabulated as follows:

. Bit Penetration Oha'm Position Factor Computing the penetration factors for the complete pattern in each of Fig. 1 and Fig. 3, We arrive at the following table of penetration factors:

From the above table, it can be seen that row 6 has the smallest penetration factor-9.60in the pattern of Fig. 1, and rows 12, 2?; and 28 have the greatest penetration factor13.52. Thus the penetration factor of row 6 is just over 71 per cent of the largest penetration factor in thepattern. The difierence in penetration factors in Fig. 3 is smaller because of the somewhat diiferent arrangement. Thus, in Fig. 3 there are three rows having a minimum penetration factor of 9.84 and three rows having a maximum penetration factor of 13.24.

At least some of the bits in each pattern are preferably arranged to provide a wedge shape. This is indicated by the dotted lines L1 and L2 of Figs. 1 and 3. The wedge shapes thus provided are preferably arranged with the point of the Wedge leading, as is indicated by the arrows at the sides of the patterns.

it will be evident to those skilled in the art that this invention provides a bit pattern in Which the penetration factor does not change radically from one roW of bits to the next, thus diminishing the shock on the veinattacking and disintegrating instrument and reducing strain, Wear and tear on the machine. Other advantages will be apparent to those skilled in the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration, and that the invention may be modified and embodied in varous other forms without departing from its spirit or the scope of the appended claims.

I claim:

1. A. developed bit pattern for the projecting disintegrating bits of a vein-attacking and disintegrating instrument having a plurality of chains carrying bit holders to move said bits in orbital paths to cause the bits to project into and penetrate a mineral in the solid and having means to move the pattern into said mineral in the solid in a direction generally normal to the movement of the bits in their orbital paths, comprising a plurality of bits arranged in rows across the several chains, the tips of the bits in each row lying in a plane and the planes of the several rows being parallel to each other and substantially perpendicular to the orbital paths, the bits extending different distances from said holders in the direction of penetration and thus having widely varying penetration factors, none of said parallel planes having bits Whose penetration factor total is less than 71 per cent of the largest total.

2. A bit pattern as set forth in claim 1, in which at least some bits are also arranged to form a wedge-shaped pattern.

3. A bit pattern as set forth in claim 2, in which the bits are arranged in a plurality of groups substantially parallel to said orbital paths, certain alined bits in each group having a maximum projection in said generally normal direction and other bits in the group on each ide of said certain bits having a lesser projection in said direction.

4. A bit pattern according to claim 3, in which the bits in each group are arranged with decreasing penetration factors as their distance increases from a plane passing through said certain alined bits.

5. A bit pattern as set forth in claim 1, in which the bits are arranged in a plurality of groups substantially parallel to said orbital paths, certain alined bits in each group having a maximum projection in said generally normal direction and other bits in the group on each side of said certain bits having a lesser projectionin said direction.

6. A bit pattern according to claim 5, in which the bits in each group are arranged with decreasing penetration factors as their distance increases from a plane passing through said certain alined bits.

7. A developed bit pattern for the projecting disintegrating bits of a vein-attacking and disintegrating instrument having a plurality of chains carrying bit blocks to move said bits in plane orbital paths to cause the bits to project into and penetrate a mineral in the solid and having means to move the pattern into said mineral in the solid in a direction generally normal to the movement of the bits in their orbital paths, comprising: a plurality of bits arranged in rows across the several chains, the tips of the bits in each row lying in a plane and the planes of said several rows being parallel to each other and extending different distances from said blocks in the direction of penetration and thus having penetration factors ranging from 1 to approximately 3.5 and no plane having bits Whose penetration factor total is less than 71 per cent of the largest total.

8. A bit pattern as set forth in claim 7, in which at least some bits are also arranged to form a wedge-shaped pattern.

9. A bit pattern as set forth in claim 8, in which the bits are arranged in each chain with certain of the bits having a maximum projection in said generally normal direction and other bits in such chain on each side of said certain bits having a lesser projection in said direction.

10. A bit pattern according to claim 9, in which the bits in each chain are arranged with decreasing penetration factors as their distance increases from a plane passing through said certain alined bits.

11. A bit pattern as set forth in claim 7, in which the bits are arranged in each chain with certain of the bits having a maximum projection in said generally normal direction and other bits in such chain on each side of said certain bits having a lesser projection in said direction.

12. A bit pattern according to claim 11, in which the bits in each chain are arranged with decreasing penetration factors as their distance increases from a plane passing through said certain alined bits.

13. A developed bit pattern for the projecting dis integrating bits of a vein-attacking and disintegrating instrument having a plurality of chains carrying bit blocks to move said bits in plane orbital paths to cause the bits to project into and penetrate a mineral in the solid and having means to move the pattern into said mineral in the solid in a direction generally normal to the movement of the bits in their orbital paths, comprising: a plurality of bits arranged in rows across the several chains, the tips of the bits in each row lying in a plane and the planes of said several rows being parallel to each other and substantially perpendicular to the planes of the orbital paths, the bits extending diiferent distances from said blocks in the direction of penetration and thus having penetration factors ranging from 1 to 3.5 and References Cited in the file of this patent UNITED STATES PATENTS 772,152 Joy Oct. 11, 1904 1,469,132 Wilson Sept. 25, 1923 1,528,546 Holmes Mar. 3, 1925 1,588,563 Wilson June 15, 1926 2,202,584 Holmes May 28, 1940 2,283,212 Joy May 19, 1942 2,587,065 I Robbins Feb. 26, 1952 2,634,963 Barrett Apr. 14, 1953 FOREIGN PATENTS 229,807 Great Britain Mar. 5, 1925 Great Britain Nov. 20, 1930 

